BIML – What is it?
I’ve noticed a growing trend over the last year – the ever growing presence of BIML (Business Intelligence Markup Language). So what is it? What does it do? And do you need to learn it?
What is BIML?
Simply, it’s a way of defining the functionality of an SSIS (Integration Services) package. If you’ve ever opened an SSIS .dtsx file in notepad you’ll see a daunting mess of GUIDs that you really don’t want to play around with. BIML is a simple XML format that allows you to write an SSIS package in notepad. When you run a BIML script it creates SSIS packages for you. These can then be opened and edited in BIDS exactly the same as an SSIS package that you’d created manually.
To show the difference, first of all this is a sample BIML script:
Then, when this is compiled into an SSIS package it looks like this in the front end:
But this when you open the .dtsx package in notepad:
The BIML script is a little easier to digest!
But why on earth would you want to do that, when you can just use the BIDS/Visual Studio GUI? The answer is C# and automation. You can mix C# code in with the BIML XML (in a similar way to PHP or old school ASP scripts). This allows you to have a single BIML script, which can apply itself to every item in a list, or every table in a database, and automatically generate all of your SSIS packages from a single template.
Yes, this is very cool stuff.
The following screenshot is the same script as above, but configured to loop through every table in the ‘dim’ schema of a data warehouse, creating a package that truncates the relevant dim table.
The C# script is highlighted in yellow for clarity.
With this, just running the script will create multiple SSIS packages at the click of a button.
How do you create and run a script?
Firstly you need BIDS Helper. But you should have that anyway.
Create a new Integration Services project, then right click on the project and click ‘Add New Biml File’
This will add a BIML script file into the Miscellaneous folder of the project.
Once you’ve written a script you can test it (right click on the script and select ‘Check Biml for Errors’, or you can run the script, generating the SSIS packages, by clicking ‘Generate SSIS Packages’.
So, do you need to learn BIML?
I have no doubt that BIML is the future of SSIS. Once you see the full power of if then you’ll never want to go back to manually coding packages again.
If you’re an SSIS pro then there’s a good chance that your next job will require BIML. Or if a potential employer doesn’t ask for it, you can certainly improve your chances of getting the job by selling it (and your skills) to them.
At Purple Frog, all of our SSIS development is now 90% automated using BIML, leaving us more time to focus on the 10% of work that need some custom tweaking or more enhanced logic.
What if you don’t like coding?
Well in that case, check out MIST from Varigence. It’s a GUI for BIML, and a lot more besides. If you’re going to be using BIML a lot then it may well be worth the investment.